In the electrophotographic process, various charging devices are needed to charge a photoreceptor (“receptor”), recharge a toner layer, charge an intermediate transfer belt for electrostatic transfer of toner, or charge a sheet of media, such as a sheet of paper. A conventional solid state charging device extracts charge, e.g., ions and/or electrons, from a high-density plasma source. The source is created by electrical gas breakdown in a high frequency AC field between two conducting electrodes, typically a coronode and one or more AC electrodes, separated by a dielectric material. The potential of the coronode, the electrode directly facing the photoreceptor, determines the polarity and magnitude of charging current. Problems arise because undesired highly reactive oxidizing species are generated in the process that degrade the photoreceptor and may cause air pollution. Moreover, in conventional solid state charging devices, charged species are generated nonuniformly across the surface of the coronode and may occur to a larger degree at the corners. To compensate, high operating temperatures are required to achieve charge uniformity. Another problem arises due to the high voltages which lead to localized breakdown of the dielectric layer that also results in non-uniform charging.
Thus, there is a need to overcome these and other problems of the prior art to provide a method and system for solid state charging of the receptor, to reduce the operating temperature and AC voltages used in the charging process, and to improve the overall operating efficiency of these devices.